This invention relates to a solenoid valve, in particular for slip-controlled brake systems of automotive vehicles, having a valve governor integrated into the valve body between a first and second pressure medium connections providing pressure medium volume control.
In industrial hydraulic engineering, there are a variety of applications for solenoid valves for controlling and regulating pressure media. Likewise, the use of solenoid valves in the equipment of vehicles is of great importance since the flows of pressure medium have to be controlled with great precision even in case of extraordinary operating conditions.
When integrating solenoid valves within the vehicle, it is of special importance to consider additional measures, both active and passive, that go beyond the actual operativeness and are a benefit to the pursuit of comfort with regard to easy service and noiselessness of the respective system controlled by solenoid valves.
As regards the desired noiselessness, reference is made, for instance, to the arrangement of pressure pulsation dampers within a valve block for a slip-controlled brake system as is known from German Published Patent Application (=DE-OS) No. 39 13 352. Because of their elastic deformability, these pulsation dampers are able to absorb the noise emissions originating from the switching frequencies of the solenoid valves so that it is possible to lower the noise level felt to be a disturbance. A disadvantage of this method, however, results from the fact that an elastic deformation of the pressure pulsation damper automatically will also result in an undesired increase in the pressure medium volume intake.
It is thus an object of this invention to set forth a solution which effectively reduces the noise level, depending on the solenoid valve operating positions, and its propagation, while maintaining an unaltered simple design of the solenoid valves as far as possible and without having to accept an additional volume intake during operation.
In accordance with this invention, this task is solved by arranging a control piston, which is integrated in the valve accommodating body and which regulates the volume or the pressure, between the pressure medium connection of the pressure medium source and the valve closure member of the solenoid valve which is open in the basic position, when currentless, with the control edge, which is effective on the control piston, adjusting the pressure medium flow in dependence on the piston stroke.
These constructional measures as well as the further characteristics and advantages of the claimed invention will be represented and explained in more detail in the following, reference being made to several drawings.